Donner D G, Elliott G E, Beck B R, Forwood M R, Du Toit E F
Heart Foundation Research Centre, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia.
School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia.
Osteoporos Int. 2016 Mar;27(3):1073-1082. doi: 10.1007/s00198-015-3345-1. Epub 2015 Oct 5.
In males, visceral obesity and androgen deficiency often present together and result in harmful effects on bone. Our findings show that both factors are independently associated with adverse effects on femoral bone structure and strength, and trenbolone protects rats from diet-induced visceral obesity and consequently normalises femoral bone structural strength.
In light of the rapidly increasing incidence of obesity and osteoporosis globally, and recent conjecture regarding the effects of visceral adiposity and testosterone deficiency on bone health, we investigated the effects of increased visceral adipose tissue (VAT) mass on femoral bone mineral density (BMD), structure and strength in normal weight rats with testosterone deficiency.
Male Wistar rats (n = 50) were fed either standard rat chow (CTRL, n = 10) or a high-fat/high-sugar diet (HF/HS, n = 40). Following 8 weeks of feeding, rats underwent sham surgery (CTRL, n = 10; HF/HS, n = 10) or orchiectomy (HF/HS + ORX, n = 30). Following a 4-week recovery period, mini-osmotic pumps containing either vehicle (CTRL, n = 10; HF/HS, n = 10; HF/HS + ORX, n = 10), 2.0 mg kg day(-1), testosterone (HF/HS + ORX + TEST, n = 10) or 2.0 mg kg day(-1) trenbolone (HF/HS + ORX + TREN, n = 10) were implanted for 8 weeks of treatment. Dual-energy X-ray absorptiometry and three-point bending tests were used to assess bone mass, structure and strength of femora.
Diet-induced visceral obesity resulted in decreased bone mineral area (BMA) and content (BMC) and impaired femoral stiffness and strength. Orchiectomy further impaired BMA, BMC and BMD and reduced energy to failure in viscerally obese animals. Both TEST and TREN treatment restored BMA, BMC, BMD and energy to failure. Only TREN reduced visceral adiposity and improved femoral stiffness and strength.
Findings support a role for both visceral adiposity and testosterone deficiency as independent risk factors for femoral osteoporosis, adverse bone geometry and impaired bone strength in male rats. Trenbolone may be a more effective candidate for androgen replacement therapy than testosterone in viscerally obese testosterone-deficient males.
在男性中，内脏肥胖和雄激素缺乏常常同时出现，并对骨骼产生有害影响。我们的研究结果表明，这两个因素均独立地与股骨的骨结构和强度的不良影响相关，而群勃龙可保护大鼠免受饮食诱导的内脏肥胖，从而使股骨的结构强度恢复正常。
鉴于全球肥胖症和骨质疏松症的发病率迅速上升，以及最近关于内脏肥胖和睾酮缺乏对骨骼健康影响的推测，我们研究了内脏脂肪组织（VAT）量增加对睾酮缺乏的正常体重大鼠股骨骨矿物质密度（BMD）、结构和强度的影响。
将50只雄性Wistar大鼠分为两组，一组喂食标准大鼠饲料（对照组，n = 10），另一组喂食高脂/高糖饮食（HF/HS，n = 40）。喂养8周后，大鼠接受假手术（对照组，n = 10；HF/HS，n = 10）或睾丸切除术（HF/HS + ORX，n = 30）。经过4周的恢复期后，对大鼠植入含有溶剂（对照组，n = 10；HF/HS，n = 10；HF/HS + ORX，n = 10）、2.0mg·kg·day⁻¹睾酮（HF/HS + ORX + TEST，n = 10）或2.0mg·kg·day⁻¹群勃龙（HF/HS + ORX + TREN，n = 10）的微型渗透泵，进行为期8周的治疗。采用双能X线吸收法和三点弯曲试验评估股骨的骨量、结构和强度。
饮食诱导的内脏肥胖导致骨矿物质面积（BMA）和骨矿物质含量（BMC）降低，股骨刚度和强度受损。睾丸切除术进一步损害了内脏肥胖动物的BMA、BMC和BMD，并降低了其破坏能量。睾酮和群勃龙治疗均恢复了BMA、BMC、BMD和破坏能量。只有群勃龙降低了内脏脂肪含量，改善了股骨刚度和强度。
研究结果支持内脏肥胖和睾酮缺乏均为雄性大鼠股骨骨质疏松、不良骨几何形状和骨强度受损的独立危险因素。在患有内脏肥胖的睾酮缺乏男性中，群勃龙可能是比睾酮更有效的雄激素替代疗法候选药物。
